2016 Vol. 34 No. 1
Abstract：
Rhododendron protistum var.giganteum is an evergreen tree that belongs to subgenus Hymenanthes and subsection Grandia from the family Ericaceae.It is a highly endangered species in a small area in the southern part of Yunnan Province in China.This plant has been listed in the Conservation Program for Wild Plants with Extremely Small Populations in China (2012-2015 Operational Plan) due to its limited distribution and small populations.In the present study, the anatomical characteristics of the leaves, stems and roots of R.protistum var.giganteum were studied by paraffin sectioning and leaf epidermal isolation.Furthermore, seed surface, stoma and indumentum characteristics were also observed under scanning electron microscope (SEM).The paraffin sectioning results indicated that the secondary structure of the root was mainly composed of periderm and vascular cylinder.The anatomical structure of the stem consisted of the epidermis, cortex, phloem, xylem and pith.The leaf was bifacial with a cuticle on the upper epidermis.The epidermal hairs and stomata were only distributed on the lower epidermis.The stomata were anomocytic type.Palisade tissue was arranged closely and was well-developed, while the spongy tissue was arranged loosely.There were well-developed vascular bundles and bundle sheath extensions distributed in the structure of the leaf.Through SEM, it was found that the foliar trichome of R.protistum var. giganteum was composed of two layers of epidermal hairs, including a layer of cavernous villi and a layer of short lamelliform villi.Basal and apical wings were equally developed on the seeds.Seeds were flattened and exotesta longitudinal sculptures, which were conformed on the dorsal and ventral sides of the seed.The results obtained in the present study will not only help to further understand the biological characteristics of this species, but also provide a scientific basis to elucidate its systematic classification and habitat adaptation.
Rhododendron protistum var.giganteum is an evergreen tree that belongs to subgenus Hymenanthes and subsection Grandia from the family Ericaceae.It is a highly endangered species in a small area in the southern part of Yunnan Province in China.This plant has been listed in the Conservation Program for Wild Plants with Extremely Small Populations in China (2012-2015 Operational Plan) due to its limited distribution and small populations.In the present study, the anatomical characteristics of the leaves, stems and roots of R.protistum var.giganteum were studied by paraffin sectioning and leaf epidermal isolation.Furthermore, seed surface, stoma and indumentum characteristics were also observed under scanning electron microscope (SEM).The paraffin sectioning results indicated that the secondary structure of the root was mainly composed of periderm and vascular cylinder.The anatomical structure of the stem consisted of the epidermis, cortex, phloem, xylem and pith.The leaf was bifacial with a cuticle on the upper epidermis.The epidermal hairs and stomata were only distributed on the lower epidermis.The stomata were anomocytic type.Palisade tissue was arranged closely and was well-developed, while the spongy tissue was arranged loosely.There were well-developed vascular bundles and bundle sheath extensions distributed in the structure of the leaf.Through SEM, it was found that the foliar trichome of R.protistum var. giganteum was composed of two layers of epidermal hairs, including a layer of cavernous villi and a layer of short lamelliform villi.Basal and apical wings were equally developed on the seeds.Seeds were flattened and exotesta longitudinal sculptures, which were conformed on the dorsal and ventral sides of the seed.The results obtained in the present study will not only help to further understand the biological characteristics of this species, but also provide a scientific basis to elucidate its systematic classification and habitat adaptation.
2016, 34(1): 9-12.
DOI: 10.11913/PSJ.2095-0837.2016.10009
Abstract：
Dendrobium luoi L.J.Chen & W.H.Rao, from Xinning County of Hunan Province, China, is described and illustrated as a new species of Orchidaceae.The new species is similar to its ally D.hekouense, but can be distinguished by its pedicel and ovary 2-2.5 cm long; flower yellowish; sepal apex red-brown; dorsal sepals narrowly elliptic; lip obovate-spatulate, unlobed with purple-brown spots; lip disc with three longitudinal lamellae extending from its base to the apex, and lamellae inflated at the middle with papilla-hairy.
Dendrobium luoi L.J.Chen & W.H.Rao, from Xinning County of Hunan Province, China, is described and illustrated as a new species of Orchidaceae.The new species is similar to its ally D.hekouense, but can be distinguished by its pedicel and ovary 2-2.5 cm long; flower yellowish; sepal apex red-brown; dorsal sepals narrowly elliptic; lip obovate-spatulate, unlobed with purple-brown spots; lip disc with three longitudinal lamellae extending from its base to the apex, and lamellae inflated at the middle with papilla-hairy.
2016, 34(1): 13-17.
DOI: 10.11913/PSJ.2095-0837.2016.10013
Abstract：
Spiradiclis yangchunensis, a new species endemic to Guangdong Province, China, is described and illustrated here. It is similar to S. howii H.S. Lo in somewhat woody stems,lanceolate leaves, linear bracts and bracteolates, and salverform flowers, but differs in having glabrous stems and leaves, scorpioid paniculiform inflorescence, small and triangular hypanthium lobes, and low position of stamens in long-styled flowers. Only one population with less than 200 individuals of S. yangchunensis was found at the type locality up to now, and its conservation status is evaluated as Endangered (EN), according to the IUCN Red List Categories and Criteria.
Spiradiclis yangchunensis, a new species endemic to Guangdong Province, China, is described and illustrated here. It is similar to S. howii H.S. Lo in somewhat woody stems,lanceolate leaves, linear bracts and bracteolates, and salverform flowers, but differs in having glabrous stems and leaves, scorpioid paniculiform inflorescence, small and triangular hypanthium lobes, and low position of stamens in long-styled flowers. Only one population with less than 200 individuals of S. yangchunensis was found at the type locality up to now, and its conservation status is evaluated as Endangered (EN), according to the IUCN Red List Categories and Criteria.
2016, 34(1): 18-20.
DOI: 10.11913/PSJ.2095-0837.2016.10018
Abstract：
Habenaria chlorina E.C. Parish & Rchb. f. (Orchidaceae), a newly recorded species, is reported from China for the first time. The species is characterized by its floral bract with marginal short hairs. It is similar to H. acuifera and H. linguella, but differs by its spur having no ridge rising in front of the entrance.
Habenaria chlorina E.C. Parish & Rchb. f. (Orchidaceae), a newly recorded species, is reported from China for the first time. The species is characterized by its floral bract with marginal short hairs. It is similar to H. acuifera and H. linguella, but differs by its spur having no ridge rising in front of the entrance.
Abstract：
Analysis of species spatial distribution and associations contribute to understanding the mechanisms of community structure.In this paper, spatial point patterns were used to analyze the spatial distribution patterns and species associations of 36 dominant species at the scale of 0-50 m in Diaoguanjing plots in the Yaoluoping National Nature Reserve.Results indicated that species were cluster distributed at the fine scale and randomly distributed at the coarse scale.No association patterns dominated at the 0-50 m scale, but the percentage of non-correlated plant species pairs was the lowest at the scale of 10 m.No positive or negative correlated plant species pairs exceeded 20% at the 0-50 m scale.We concluded that the secondary community, habitat heterogeneity and dispersal limitation were the main factors responsible for the patterns of species distribution and associations in the studied plots.Our results will help to improve understanding of the multi-scale characteristics and mechanisms of species coexistence.
Analysis of species spatial distribution and associations contribute to understanding the mechanisms of community structure.In this paper, spatial point patterns were used to analyze the spatial distribution patterns and species associations of 36 dominant species at the scale of 0-50 m in Diaoguanjing plots in the Yaoluoping National Nature Reserve.Results indicated that species were cluster distributed at the fine scale and randomly distributed at the coarse scale.No association patterns dominated at the 0-50 m scale, but the percentage of non-correlated plant species pairs was the lowest at the scale of 10 m.No positive or negative correlated plant species pairs exceeded 20% at the 0-50 m scale.We concluded that the secondary community, habitat heterogeneity and dispersal limitation were the main factors responsible for the patterns of species distribution and associations in the studied plots.Our results will help to improve understanding of the multi-scale characteristics and mechanisms of species coexistence.
Abstract：
Following manual collection of seeds stored in sand under low temperature and then cultivated in greenhouse, Machilus pauhoi,Cinnamomum camphora and Phoebe bournei (Lauraceae) seedlings from the mid-subtropical zone of China were transplanted to the common garden in the Jiangxi Dagangshan Forest Ecosystem Research Station.Interspecific differences and correlations in leaf size, leaf thickness, leaf volume, leaf tissue density, specific leaf area, leaf dry matter content, leaf nitrogen concentration, leaf phosphorus concentration, and ratio of nitrogen and phosphorus concentration of two-year old seedlings in the growing season were investigated to provide basic data and scientific reference material on the responses of the leaf functional traits to global climate change.Results showed that: (1) Among the three plant seedlings, leaf size, leaf thickness, leaf volume, leaf nitrogen content and ratio of leaf nitrogen and phosphorus concentration were highest in C.camphora, and leaf tissue density was lowest.Leaf tissue density, leaf dry matter content and leaf phosphorus concentration were highest in P.bournei,while leaf size, leaf volume, specific leaf size, ratio of leaf nitrogen and phosphorus concentration, and leaf nitrogen content were lowest.Specific leaf area was highest in M.pauhoi, while leaf thickness, leaf dry matter content, and leaf phosphorus concentration were lowest.Leaf thickness of the three plant seedling species showed no significant differences; (2) Pearson and line regression analyses indicated that leaf size showed highly significant positive correlation with leaf volume (P < 0.01), and highly significant negative correlation with leaf dry matter content and leaf phosphorus concentration (P < 0.01).The correlations between leaf size and leaf tissue density and leaf nitrogen concentration were significantly negative and positive, respectively (P < 0.05).The correlations between leaf thickness and specific leaf area and leaf dry matter content were significantly negative and positive, respectively (P < 0.05).The correlations between leaf volume and leaf tissue density and leaf nitrogen concentration were highly significantly negative and positive, respectively (P < 0.01).Leaf volume also showed significant negative correlation with leaf phosphorus concentration (P < 0.05).Leaf tissue density showed significant positive correlation with leaf phosphorus concentration (P < 0.05).Specific leaf area exhibited highly significant positive correlation with leaf dry matter content and leaf phosphorus concentration, respectively (P < 0.01).Leaf dry matter content showed highly significant positive correlation with leaf phosphorus concentration (P < 0.01).The nine leaf structural traits of the three plant seedlings of Lauraceae exhibited certain interspecific differences, but the order and significance were different.Furthermore, the correlations and significance of the nine leaf structural traits of the three plant seedlings were different.
Following manual collection of seeds stored in sand under low temperature and then cultivated in greenhouse, Machilus pauhoi,Cinnamomum camphora and Phoebe bournei (Lauraceae) seedlings from the mid-subtropical zone of China were transplanted to the common garden in the Jiangxi Dagangshan Forest Ecosystem Research Station.Interspecific differences and correlations in leaf size, leaf thickness, leaf volume, leaf tissue density, specific leaf area, leaf dry matter content, leaf nitrogen concentration, leaf phosphorus concentration, and ratio of nitrogen and phosphorus concentration of two-year old seedlings in the growing season were investigated to provide basic data and scientific reference material on the responses of the leaf functional traits to global climate change.Results showed that: (1) Among the three plant seedlings, leaf size, leaf thickness, leaf volume, leaf nitrogen content and ratio of leaf nitrogen and phosphorus concentration were highest in C.camphora, and leaf tissue density was lowest.Leaf tissue density, leaf dry matter content and leaf phosphorus concentration were highest in P.bournei,while leaf size, leaf volume, specific leaf size, ratio of leaf nitrogen and phosphorus concentration, and leaf nitrogen content were lowest.Specific leaf area was highest in M.pauhoi, while leaf thickness, leaf dry matter content, and leaf phosphorus concentration were lowest.Leaf thickness of the three plant seedling species showed no significant differences; (2) Pearson and line regression analyses indicated that leaf size showed highly significant positive correlation with leaf volume (P < 0.01), and highly significant negative correlation with leaf dry matter content and leaf phosphorus concentration (P < 0.01).The correlations between leaf size and leaf tissue density and leaf nitrogen concentration were significantly negative and positive, respectively (P < 0.05).The correlations between leaf thickness and specific leaf area and leaf dry matter content were significantly negative and positive, respectively (P < 0.05).The correlations between leaf volume and leaf tissue density and leaf nitrogen concentration were highly significantly negative and positive, respectively (P < 0.01).Leaf volume also showed significant negative correlation with leaf phosphorus concentration (P < 0.05).Leaf tissue density showed significant positive correlation with leaf phosphorus concentration (P < 0.05).Specific leaf area exhibited highly significant positive correlation with leaf dry matter content and leaf phosphorus concentration, respectively (P < 0.01).Leaf dry matter content showed highly significant positive correlation with leaf phosphorus concentration (P < 0.01).The nine leaf structural traits of the three plant seedlings of Lauraceae exhibited certain interspecific differences, but the order and significance were different.Furthermore, the correlations and significance of the nine leaf structural traits of the three plant seedlings were different.
Abstract：
Seed germination by direct seeding and the survival rate and growth of seedlings for two tree species, Cyclobalanopsis glauca and Malania oleifera, were monitored by field plot experiment in three site types (bare, grass and shrub lands) in rocky desertification mountains of southwest Guangxi.The litter reserves and microclimate in summer were also surveyed in the three sites.Results showed that the litter reserves in shrub and grass land were (182.55 ± 47.94) g/m2 and (99.88 ± 35.76) g/m2, respectively.Compared with bare land, grass and shrub land obviously reduced light intensity and air temperature and increased relative air humidity in a range of 150 cm from the ground, with the effects becoming more obvious nearer to the ground.In addition, grass and shrub land also markedly decreased soil temperature underground to a depth of 5 cm.The seed germination, seedling survival rate and height increment of C.glauca did not significantly vary among the three sites (P> 0.05).However, for M.oleifera, seed germination was obviously different between bare land and shrub land (P= 0.014), height increment of seedling was obviously different between bare land and shrub land and between grass land and shrub land (P= 0.011 and P= 0.041, respectively), and seedling basal diameter growth was significantly different between bare land and shrub land (P= 0.043) and between grass land and shrub land (P= 0.003).Our results preliminarily indicated that seed germination was higher and seedlings grew faster for M.oleifera under shrub and grass conditions, and should be considered for afforestation in rocky desertification mountains in Southwest Guangxi.Due to the very high mortality rate of annual C.glauca seedlings over winter, seedling treatment and care should be improved or other afforestation methods taken to achieve the desired results.
Seed germination by direct seeding and the survival rate and growth of seedlings for two tree species, Cyclobalanopsis glauca and Malania oleifera, were monitored by field plot experiment in three site types (bare, grass and shrub lands) in rocky desertification mountains of southwest Guangxi.The litter reserves and microclimate in summer were also surveyed in the three sites.Results showed that the litter reserves in shrub and grass land were (182.55 ± 47.94) g/m2 and (99.88 ± 35.76) g/m2, respectively.Compared with bare land, grass and shrub land obviously reduced light intensity and air temperature and increased relative air humidity in a range of 150 cm from the ground, with the effects becoming more obvious nearer to the ground.In addition, grass and shrub land also markedly decreased soil temperature underground to a depth of 5 cm.The seed germination, seedling survival rate and height increment of C.glauca did not significantly vary among the three sites (P> 0.05).However, for M.oleifera, seed germination was obviously different between bare land and shrub land (P= 0.014), height increment of seedling was obviously different between bare land and shrub land and between grass land and shrub land (P= 0.011 and P= 0.041, respectively), and seedling basal diameter growth was significantly different between bare land and shrub land (P= 0.043) and between grass land and shrub land (P= 0.003).Our results preliminarily indicated that seed germination was higher and seedlings grew faster for M.oleifera under shrub and grass conditions, and should be considered for afforestation in rocky desertification mountains in Southwest Guangxi.Due to the very high mortality rate of annual C.glauca seedlings over winter, seedling treatment and care should be improved or other afforestation methods taken to achieve the desired results.
2016, 34(1): 47-55.
DOI: 10.11913/PSJ.2095-0837.2016.10047
Abstract：
Competition between aquatic plants plays a crucial role in ecosystem recovery in water bodies. Replacement series experiments were performed to explore the interspecific competition between Myriophyllum spicatum L. and Vallisneria natans (Lour.) Hara at different growth stages. Results showed that competitive capacity of M. spicatum L. was superior to that of V. natans (Lour.) Hara whether it was in the seedling or adult stage. Comparatively speaking, adult stage V. natans (Lour.) Hara had an advantage over its seedling stage. The average height of M. spicatum L. grown with V. natans (Lour.) Hara in the adult stage was 128.6% (P< 0.05) higher than that grown with V. natans (Lour.) Hara in the seedling stage, whereas the average dry weight of M. spicatum L. was 62.8% (P< 0.05) lower. The M. spicatum L. grown with V. natans (Lour.) Hara in the seedling stage had more branches and larger plant plexus, thus forming a larger canopy and restraining light use by V. natans (Lour.) Hara seedlings. In contrast, M. spicatum L. grown with adult V. natans (Lour.) Hara had fewer branches, longer plants, and its top floated on the water, which was obviously inhibited due to increased competition from V. natans (Lour.) Hara, though this was less than the intraspecific competition of M. spicatum L. In addition, the average root length of seedling stage V. natans (Lour.) Hara was 28.6% (P< 0.05) longer than that of adult stage V. natans (Lour.) Hara in competition with M. spicatum L., which tended to compete for resources underground. This study showed that the competitive capacity of M. spicatum L. was superior to that of V. natans (Lour.) Hara, and seedling stage V. natans (Lour.) Hara was significantly impacted by competition with M. spicatum L.
Competition between aquatic plants plays a crucial role in ecosystem recovery in water bodies. Replacement series experiments were performed to explore the interspecific competition between Myriophyllum spicatum L. and Vallisneria natans (Lour.) Hara at different growth stages. Results showed that competitive capacity of M. spicatum L. was superior to that of V. natans (Lour.) Hara whether it was in the seedling or adult stage. Comparatively speaking, adult stage V. natans (Lour.) Hara had an advantage over its seedling stage. The average height of M. spicatum L. grown with V. natans (Lour.) Hara in the adult stage was 128.6% (P< 0.05) higher than that grown with V. natans (Lour.) Hara in the seedling stage, whereas the average dry weight of M. spicatum L. was 62.8% (P< 0.05) lower. The M. spicatum L. grown with V. natans (Lour.) Hara in the seedling stage had more branches and larger plant plexus, thus forming a larger canopy and restraining light use by V. natans (Lour.) Hara seedlings. In contrast, M. spicatum L. grown with adult V. natans (Lour.) Hara had fewer branches, longer plants, and its top floated on the water, which was obviously inhibited due to increased competition from V. natans (Lour.) Hara, though this was less than the intraspecific competition of M. spicatum L. In addition, the average root length of seedling stage V. natans (Lour.) Hara was 28.6% (P< 0.05) longer than that of adult stage V. natans (Lour.) Hara in competition with M. spicatum L., which tended to compete for resources underground. This study showed that the competitive capacity of M. spicatum L. was superior to that of V. natans (Lour.) Hara, and seedling stage V. natans (Lour.) Hara was significantly impacted by competition with M. spicatum L.
Abstract：
Selective cutting operation under different intensities (control 0%, low intensity 20.6%, middle intensity 29.9%, and high intensity 41.6%) was established in a natural spruce-fir forest in Jingouling forest farm to quantitatively analyze the dynamic changes in species composition and diversity in the tree layer and establish intensity suitability. Results indicated that after 10 years of restoration, selective cutting had little effect on the original structure of the forest, and low and middle intensity selective cutting maintained the pre-cutting tree species structure such that the fir species were dominant, while pine and spruce were sub-dominant. High selective cutting changed the structure slightly, but not significantly. Compared with that before selective cutting, the α diversity indices of all selective cutting plots after 10 years of restoration increased and the dominance index exhibited different degrees of reduction. The increase in species richness, diversity and evenness and the decrease in the dominance index of the selective cutting plots under low intensity were greatest. This showed that low intensity selective cutting was beneficial for forest species diversity and richness. Furthermore, this study demonstrated that low intensity selective cutting was more advanta-geous to the maintenance of species structure and diversity and to the development and sustainable management of the natural spruce-fir forest.
Selective cutting operation under different intensities (control 0%, low intensity 20.6%, middle intensity 29.9%, and high intensity 41.6%) was established in a natural spruce-fir forest in Jingouling forest farm to quantitatively analyze the dynamic changes in species composition and diversity in the tree layer and establish intensity suitability. Results indicated that after 10 years of restoration, selective cutting had little effect on the original structure of the forest, and low and middle intensity selective cutting maintained the pre-cutting tree species structure such that the fir species were dominant, while pine and spruce were sub-dominant. High selective cutting changed the structure slightly, but not significantly. Compared with that before selective cutting, the α diversity indices of all selective cutting plots after 10 years of restoration increased and the dominance index exhibited different degrees of reduction. The increase in species richness, diversity and evenness and the decrease in the dominance index of the selective cutting plots under low intensity were greatest. This showed that low intensity selective cutting was beneficial for forest species diversity and richness. Furthermore, this study demonstrated that low intensity selective cutting was more advanta-geous to the maintenance of species structure and diversity and to the development and sustainable management of the natural spruce-fir forest.
Abstract：
Based on field survey data from 24 plots, we studied the forest community species diversity using the species richness, Shannon-Wiener and Jaccard similarity indices and the influencing factors in the rock stream periglacial landforms of Mt. Laotudingzi. The results showed that: (1) The average species richness index values for the deciduous broad-leaf, mixed broadleaf-conifer, and dark coniferous forests were 41 ± 10, 34 ± 5 and 31 ± 7, respectively. The variation coefficients of the species richness index of the forest community exhibited moderate variability. (2) The average Shannon-Wiener index values for the deciduous broad-leaved, mixed broadleaf-conifer, and dark coniferous forests were 1.67 ± 0.32, 1.50 ± 0.18 and 1.29 ± 0.25, respectively. (3) Similarity index values among plant populations of the rock stream periglacial landforms varied between 0.037 and 0.530, and were concentrated in two intervals of 0.25-0.5 and 0-0.25. (4) Correlation analysis showed that rock stream periglacial landforms altitude had a significant negative correlation with the species richness and Shannon-Wiener index of the forest community tree layer (P < 0.01), and an obvious negative correlation with the species richness of the shrub layer (P < 0.05). Both soil electrical conductivity and salt content had obvious positive correlations with species diversity of forest community in the rock stream periglacial landforms (P < 0.05). The pH value of the soil had a significant positive correlation with the species richness and Shannon-Wiener index of the shrub layer (P < 0.01). The CaO content in the soil had an obvious positive correlation with the Shannon-Wiener index and species richness of the tree and shrub layers (P < 0.05). Therefore, changes in plant diversity of the rock stream periglacial landforms were primarily influenced by altitude and the electrical conductivity, salt content, pH value and CaO content of the soil.
Based on field survey data from 24 plots, we studied the forest community species diversity using the species richness, Shannon-Wiener and Jaccard similarity indices and the influencing factors in the rock stream periglacial landforms of Mt. Laotudingzi. The results showed that: (1) The average species richness index values for the deciduous broad-leaf, mixed broadleaf-conifer, and dark coniferous forests were 41 ± 10, 34 ± 5 and 31 ± 7, respectively. The variation coefficients of the species richness index of the forest community exhibited moderate variability. (2) The average Shannon-Wiener index values for the deciduous broad-leaved, mixed broadleaf-conifer, and dark coniferous forests were 1.67 ± 0.32, 1.50 ± 0.18 and 1.29 ± 0.25, respectively. (3) Similarity index values among plant populations of the rock stream periglacial landforms varied between 0.037 and 0.530, and were concentrated in two intervals of 0.25-0.5 and 0-0.25. (4) Correlation analysis showed that rock stream periglacial landforms altitude had a significant negative correlation with the species richness and Shannon-Wiener index of the forest community tree layer (P < 0.01), and an obvious negative correlation with the species richness of the shrub layer (P < 0.05). Both soil electrical conductivity and salt content had obvious positive correlations with species diversity of forest community in the rock stream periglacial landforms (P < 0.05). The pH value of the soil had a significant positive correlation with the species richness and Shannon-Wiener index of the shrub layer (P < 0.01). The CaO content in the soil had an obvious positive correlation with the Shannon-Wiener index and species richness of the tree and shrub layers (P < 0.05). Therefore, changes in plant diversity of the rock stream periglacial landforms were primarily influenced by altitude and the electrical conductivity, salt content, pH value and CaO content of the soil.
2016, 34(1): 78-88.
DOI: 10.11913/PSJ.2095-0837.2016.10078
Abstract：
We studied the flora and composition of seed plant species in the Kumtag Desert, a typical region in northwest China, by field investigation and remote sensing. The results showed that: (1) There were 143 plant species belonging to 29 families and 91 genera. Among these species, annual and perennial plants were the main life forms. The species composition was deficient, and plant life-form was simple. (2) The Aqik Valley, piedmont alluvial-pluvial fan of the Arjin Mountain, and Xihu Wetland formed three distinct seed plant distribution areas in the Kumtag Desert, which were influenced by water, high temperature and soil salinity. The differences in species composition for the three regions were significant. (3) The life forms in the piedmont alluvial-pluvial fan of the Arjin Mountain were richer than those in the Aqik Valley or Xihu Wetland. Additionally, the piedmont alluvial-pluvial fan of the Arjin Mountain had the richest families, genera and species. Higher similarities in genus and species were observed between the Aqik Valley and Xihu Wetland. (4) Chenopodiaceae, Compositae and Ephedraceae were the dominant families in the Kumtag Desert. The main distribution pattern of the families in the three regions was Cosmopolitan. The main geographical elements of all genera in the Kumtag Desert were Mediterranea. W. Asia to C. Asia in the Aqik Valley and Xihu Wetland, and North Temperate in the piedmont alluvial-pluvial fan of the Arjin Mountain. (5) Compared with the near desert regions, the ratio of xerophytes was higher in the Kumtag Desert, and the relic nature was more obvious. Special seed plant taxa and flora features were formed because of the particular Kumtag Desert environment.
We studied the flora and composition of seed plant species in the Kumtag Desert, a typical region in northwest China, by field investigation and remote sensing. The results showed that: (1) There were 143 plant species belonging to 29 families and 91 genera. Among these species, annual and perennial plants were the main life forms. The species composition was deficient, and plant life-form was simple. (2) The Aqik Valley, piedmont alluvial-pluvial fan of the Arjin Mountain, and Xihu Wetland formed three distinct seed plant distribution areas in the Kumtag Desert, which were influenced by water, high temperature and soil salinity. The differences in species composition for the three regions were significant. (3) The life forms in the piedmont alluvial-pluvial fan of the Arjin Mountain were richer than those in the Aqik Valley or Xihu Wetland. Additionally, the piedmont alluvial-pluvial fan of the Arjin Mountain had the richest families, genera and species. Higher similarities in genus and species were observed between the Aqik Valley and Xihu Wetland. (4) Chenopodiaceae, Compositae and Ephedraceae were the dominant families in the Kumtag Desert. The main distribution pattern of the families in the three regions was Cosmopolitan. The main geographical elements of all genera in the Kumtag Desert were Mediterranea. W. Asia to C. Asia in the Aqik Valley and Xihu Wetland, and North Temperate in the piedmont alluvial-pluvial fan of the Arjin Mountain. (5) Compared with the near desert regions, the ratio of xerophytes was higher in the Kumtag Desert, and the relic nature was more obvious. Special seed plant taxa and flora features were formed because of the particular Kumtag Desert environment.
2016, 34(1): 89-98.
DOI: 10.11913/PSJ.2095-0837.2016.10089
Abstract：
Camellia longistyla Chang ex F.A. Zeng et H. Zhou is a rare, endangered and endemic economic plant in Guizhou Province, China. This species is distributed narrowly from 950 to 1400 m elevation in mixed evergreen and broad-leaf deciduous forests in the Jinshagou Alsophila spinulosa Natural Reserve and Leigongshan Natural Reserve. We surveyed naturally-occurring C. longistyla by establishing sampling plots in two typical densely-covered areas (Wangxiangpo A and Fangshan B). Time-specific life tables and survival function curves were established and drawn based on diameter class. We analyzed the survival curve (ln(ln)) and survival function curve (Sn), and predicted population development trends by population quantity dynamics (Vn, Vpi) and time-sequence models. Results showed that: On the whole, the age structure of the C. longistyla population was declining type in the early stages, indicating more middle-aged trees and fewer young individuals. The survival curve was Deevey-Ⅰ type. Time-specific life table analysis and correlation curves revealed that the population structure of C. longistyla exhibited a slump in the early stage, stability in the middle stage and gradual decline in the late stage. According to the population dynamic analysis results, seedling supplementation was insufficient in both populations and natural regeneration was difficult, although there was a certain recovery potential. Furthermore, population A was sensitive to changes in the environment. Time-sequence analysis indicated that the decline in the two populations began in the last 1-2 age-class time. If effective protective measures are not taken, after four age-classes, the native populations will become typical declining type. With systematic study on population characteristics and propagation, together with strengthened in-situ conservation, artificially-cultivated seedlings can be returned to original habitat or introduced to similar habitat so as to increase population and dispersal ability. Such measures will be of great significance for the effective protection, development and utilization of C. longistyla germplasm resources.
Camellia longistyla Chang ex F.A. Zeng et H. Zhou is a rare, endangered and endemic economic plant in Guizhou Province, China. This species is distributed narrowly from 950 to 1400 m elevation in mixed evergreen and broad-leaf deciduous forests in the Jinshagou Alsophila spinulosa Natural Reserve and Leigongshan Natural Reserve. We surveyed naturally-occurring C. longistyla by establishing sampling plots in two typical densely-covered areas (Wangxiangpo A and Fangshan B). Time-specific life tables and survival function curves were established and drawn based on diameter class. We analyzed the survival curve (ln(ln)) and survival function curve (Sn), and predicted population development trends by population quantity dynamics (Vn, Vpi) and time-sequence models. Results showed that: On the whole, the age structure of the C. longistyla population was declining type in the early stages, indicating more middle-aged trees and fewer young individuals. The survival curve was Deevey-Ⅰ type. Time-specific life table analysis and correlation curves revealed that the population structure of C. longistyla exhibited a slump in the early stage, stability in the middle stage and gradual decline in the late stage. According to the population dynamic analysis results, seedling supplementation was insufficient in both populations and natural regeneration was difficult, although there was a certain recovery potential. Furthermore, population A was sensitive to changes in the environment. Time-sequence analysis indicated that the decline in the two populations began in the last 1-2 age-class time. If effective protective measures are not taken, after four age-classes, the native populations will become typical declining type. With systematic study on population characteristics and propagation, together with strengthened in-situ conservation, artificially-cultivated seedlings can be returned to original habitat or introduced to similar habitat so as to increase population and dispersal ability. Such measures will be of great significance for the effective protection, development and utilization of C. longistyla germplasm resources.
2016, 34(1): 99-108.
DOI: 10.11913/PSJ.2095-0837.2016.10099
Abstract：
Based on EST sequence and RACE experiments, the full-length coding sequence of a tonoplast intrinsic protein (TIP) gene termed ScTIP1;1 was cloned from Stipa capillacea. Sequence analysis showed that the opening reading frame (ORF) of ScTIP1;1 was 753 bp, encoding a 250 amino acid peptide with a protein molecular weight of 25.8 kD and isoelectric point of 6.16. Phylogenetic analysis and sequence alignment results indicated that ScTIP1;1 had a close relationship with AtTIP1;1 of Arabidopsis thaliana. Subcellular localization analysis indicated that ScTIP1;1 was localized in the tonoplast membrane. The expression level of ScTIP1;1 was induced by salt, drought and especially low temperature in the leaves of S. capillacea. These results provide new insight into understanding the ecological adaptations of S.capillacea.
Based on EST sequence and RACE experiments, the full-length coding sequence of a tonoplast intrinsic protein (TIP) gene termed ScTIP1;1 was cloned from Stipa capillacea. Sequence analysis showed that the opening reading frame (ORF) of ScTIP1;1 was 753 bp, encoding a 250 amino acid peptide with a protein molecular weight of 25.8 kD and isoelectric point of 6.16. Phylogenetic analysis and sequence alignment results indicated that ScTIP1;1 had a close relationship with AtTIP1;1 of Arabidopsis thaliana. Subcellular localization analysis indicated that ScTIP1;1 was localized in the tonoplast membrane. The expression level of ScTIP1;1 was induced by salt, drought and especially low temperature in the leaves of S. capillacea. These results provide new insight into understanding the ecological adaptations of S.capillacea.
2016, 34(1): 109-116.
DOI: 10.11913/PSJ.2095-0837.2016.10109
Abstract：
To determine the genetic structure of natural Myriophyllum spicatum populations in mainland China and the possible mechanism that led to the widely distributed pattern of the species, eight populations were examined for preliminary genetic analysis based on three chloroplast DNA segments (trnK-matK, trnL-trnF, rpl32-trnL). The AMOVA analysis results showed that the genetic diversity among the eight populations was 84.97% and within the populations was 15.03%. Furthermore, the population genetic differentiation coefficient (Fst) was 0.85, indicating high genetic diversity in M. spicatum (Hd=0.83) among populations. The founder effect may have led to the initial genetic differences and segregation barriers (Nm=0.09) may have further resulted in genetic differentiation among populations. From the constructed phylogenetic tree and haplotype network based on 17 haplotypes, haplotypes H5 and H6 had the highest frequency and widest distribution, indicating they were possibly the oldest ancestral haplotypes. The Mantel test showed no significant correlation between genetic and geographic distances among populations, and the mismatch distribution test showed that historic M. spicatum populations likely experienced expansion events. Tajima's, Fu & Li's D* and F* tests showed that this species did not have an obvious phylogeographic pattern, which may have resulted from long distance dispersal of seeds.
To determine the genetic structure of natural Myriophyllum spicatum populations in mainland China and the possible mechanism that led to the widely distributed pattern of the species, eight populations were examined for preliminary genetic analysis based on three chloroplast DNA segments (trnK-matK, trnL-trnF, rpl32-trnL). The AMOVA analysis results showed that the genetic diversity among the eight populations was 84.97% and within the populations was 15.03%. Furthermore, the population genetic differentiation coefficient (Fst) was 0.85, indicating high genetic diversity in M. spicatum (Hd=0.83) among populations. The founder effect may have led to the initial genetic differences and segregation barriers (Nm=0.09) may have further resulted in genetic differentiation among populations. From the constructed phylogenetic tree and haplotype network based on 17 haplotypes, haplotypes H5 and H6 had the highest frequency and widest distribution, indicating they were possibly the oldest ancestral haplotypes. The Mantel test showed no significant correlation between genetic and geographic distances among populations, and the mismatch distribution test showed that historic M. spicatum populations likely experienced expansion events. Tajima's, Fu & Li's D* and F* tests showed that this species did not have an obvious phylogeographic pattern, which may have resulted from long distance dispersal of seeds.
Abstract：
Chinese savanna evergreen plants can tolerate prolonged drought stress for more than half a year, but the mechanisms underlying the eco-physiological responses of these evergreen plants to drought stress are poorly understood. We selected a dominant evergreen species, Tarenna depauperata Hutchins, in this study and measured predawn leaf water potential, pressure-volume curves, leaf gas exchange, leaf spectral traits, chlorophyll fluorescence and P700 in the rainy and dry seasons, respectively. Results showed that predawn leaf water potential (Ψpd) decreased to-4.5 MPa in the dry season. Compared with the values in the rainy season, leaf specific hydraulic conductivity (KL) decreased by 49.5%, the chlorophyll reflectance index (NDVI) decreased by 40.6%, and the anthocyanin reflectance index (ARI) increased to 0.074 in the dry season, which was 12.3 times as much as the value of the rainy season. The seasonal differences in Ψpd, KL, NDVI and ARI were significant (P< 0.05). The maximum quantum yield of PSⅡ (Fv/Fm) decreased from 0.8 in the rainy season to 0.72 in the dry season (P< 0.05), indicating photoinhibition in PSⅡ; however, the activity of PSⅠ (Pm) remained stable during peak drought. In addition, maximum non-photochemical quenching (NPQ) increased by 31% and the maximum cyclic electron flow (CEF) decreased by 66% in the dry season compared with those in the rainy season. These results suggested that CEF was significantly inhibited by prolonged seasonal drought. The downregulation of light harvesting efficiency and the enhancement of NPQ played important roles in the photoprotection of this Chinese savanna evergreen woody species.
Chinese savanna evergreen plants can tolerate prolonged drought stress for more than half a year, but the mechanisms underlying the eco-physiological responses of these evergreen plants to drought stress are poorly understood. We selected a dominant evergreen species, Tarenna depauperata Hutchins, in this study and measured predawn leaf water potential, pressure-volume curves, leaf gas exchange, leaf spectral traits, chlorophyll fluorescence and P700 in the rainy and dry seasons, respectively. Results showed that predawn leaf water potential (Ψpd) decreased to-4.5 MPa in the dry season. Compared with the values in the rainy season, leaf specific hydraulic conductivity (KL) decreased by 49.5%, the chlorophyll reflectance index (NDVI) decreased by 40.6%, and the anthocyanin reflectance index (ARI) increased to 0.074 in the dry season, which was 12.3 times as much as the value of the rainy season. The seasonal differences in Ψpd, KL, NDVI and ARI were significant (P< 0.05). The maximum quantum yield of PSⅡ (Fv/Fm) decreased from 0.8 in the rainy season to 0.72 in the dry season (P< 0.05), indicating photoinhibition in PSⅡ; however, the activity of PSⅠ (Pm) remained stable during peak drought. In addition, maximum non-photochemical quenching (NPQ) increased by 31% and the maximum cyclic electron flow (CEF) decreased by 66% in the dry season compared with those in the rainy season. These results suggested that CEF was significantly inhibited by prolonged seasonal drought. The downregulation of light harvesting efficiency and the enhancement of NPQ played important roles in the photoprotection of this Chinese savanna evergreen woody species.
2016, 34(1): 127-134.
DOI: 10.11913/PSJ.2095-0837.2016.10127
Abstract：
Different embryo-aged Paphiopedilum concolor seeds were collected and their structure, germination process, and effective regeneration conditions were investigated. Results showed that the seeds collected from 210-240 days after pollination (DAP) were optimum for culture in vitro, and the seed germination percentage of 210 DAP was the highest (77.79%). Furthermore, 1/4 MS (Murashige and Skoog culture medium) and 1/2 MS were both suitable for germination, and the addition of 100 mL/L coconut water (CW) and 1 g/L peptone had a positive effect on seed germination and protocorm differentiation. The addition of 1 g/L activated charcoal (AC) inhibited protocorm browning and death, while the addition of 2 g/L AC increased the browning and mortality rates. Banana juice and apple juice had a negative effect on seed germination and protocorm differentiation. After culturing of transferred differentiation protocorm on rooting medium for 120 days, the healthy robust seedlings were 3-5 cm tall and had 5-6 leaves.
Different embryo-aged Paphiopedilum concolor seeds were collected and their structure, germination process, and effective regeneration conditions were investigated. Results showed that the seeds collected from 210-240 days after pollination (DAP) were optimum for culture in vitro, and the seed germination percentage of 210 DAP was the highest (77.79%). Furthermore, 1/4 MS (Murashige and Skoog culture medium) and 1/2 MS were both suitable for germination, and the addition of 100 mL/L coconut water (CW) and 1 g/L peptone had a positive effect on seed germination and protocorm differentiation. The addition of 1 g/L activated charcoal (AC) inhibited protocorm browning and death, while the addition of 2 g/L AC increased the browning and mortality rates. Banana juice and apple juice had a negative effect on seed germination and protocorm differentiation. After culturing of transferred differentiation protocorm on rooting medium for 120 days, the healthy robust seedlings were 3-5 cm tall and had 5-6 leaves.
Abstract：
Orchid entophytic bacteria and mycorrhizal fungi grown in collaboration can have a positive effect on host plants in terms of disease resistance, stress tolerance and phytoremediation. Understanding the endogenous relationship between bacterial diversity and habitat can reveal the adaptation and evolution mechanisms of orchid plants. The endogenous bacterial diversity and spatial heterogeneity in different habitats of Phalaenopsis pulcherrima, an endemic Southeast Asian orchid species, were analysed by molecular techniques. Fifty-nine strains of entophytic bacteria were isolated from the roots of P. pulcherrima in different habitats, including forty-five (76.27%) and fourteen (23.73%) strains of entophytic bacteria isolated from land-borne and stone-borne type populations, respectively. Based on 16S rDNA sequence analysis, fifty-nine strains of entophytic bacteria isolated from P. pulcherrima were classified into seven genera, that was, Bacillus, Burkholderia, Pandoraea, Agrobacterium, Paenibacillus, Pantoea, and Erwinia. Among the entophytic bacterial strains, Bacillus was the dominant genus, followed by Pantoea and Burkholderia. The diversity index of land-borne type populations was greater than that of stone-borne type populations. Analysis of molecular variance (AMOVA) also showed that the entophytic bacterial community structures of P. pulcherrima in distinct habitats were significantly different (P < 0.01), with land-type dominant species found in Bacillus and Pantoea, and stone-type dominant species found in Bacillus and Burkholderia.
Orchid entophytic bacteria and mycorrhizal fungi grown in collaboration can have a positive effect on host plants in terms of disease resistance, stress tolerance and phytoremediation. Understanding the endogenous relationship between bacterial diversity and habitat can reveal the adaptation and evolution mechanisms of orchid plants. The endogenous bacterial diversity and spatial heterogeneity in different habitats of Phalaenopsis pulcherrima, an endemic Southeast Asian orchid species, were analysed by molecular techniques. Fifty-nine strains of entophytic bacteria were isolated from the roots of P. pulcherrima in different habitats, including forty-five (76.27%) and fourteen (23.73%) strains of entophytic bacteria isolated from land-borne and stone-borne type populations, respectively. Based on 16S rDNA sequence analysis, fifty-nine strains of entophytic bacteria isolated from P. pulcherrima were classified into seven genera, that was, Bacillus, Burkholderia, Pandoraea, Agrobacterium, Paenibacillus, Pantoea, and Erwinia. Among the entophytic bacterial strains, Bacillus was the dominant genus, followed by Pantoea and Burkholderia. The diversity index of land-borne type populations was greater than that of stone-borne type populations. Analysis of molecular variance (AMOVA) also showed that the entophytic bacterial community structures of P. pulcherrima in distinct habitats were significantly different (P < 0.01), with land-type dominant species found in Bacillus and Pantoea, and stone-type dominant species found in Bacillus and Burkholderia.
2016, 34(1): 143-150.
DOI: 10.11913/PSJ.2095-0837.2016.10143
Abstract：
An efficient micropropagation protocol was developed for Paeonia × lemoinei ‘High Noon’ using axillary buds as explants. During initiation, 13 propagules were obtained after 50 d of culture with WPM + 0.5 mg/L BA + 0.2 mg/L GA3. During proliferation, three shoots were obtained after 35 d of culture with WPM[1668 mg/L Ca(NO3)2·4 H2O] + 0.5 mg/L BA + 0.2 mg/L GA3, and seven subcultures were carried out. For optimal rooting, the shoots were cultured with 1/2 MS (296 mg/L CaCl2) + 0.5 g/L activated charcoal for 20 d, then 1/2 MS (296 mg/L CaCl2) + 1.0 mg/L putrescine + 1.0 mg/L IBA for 30 d for root induction, and finally 1/2 MS (296 mg/L CaCl2) ＋ 4.0 g/L activated charcoal for 20 d for root development. The rooting percentage of the shoots was 77.2%. During acclimatization, the rooted plantlets were transferred to pots containing a mix of vermiculite/peat/perlite (1:1:1 V/V/V) substrate, and the survival rate was 92.1%. The micropropagation protocol for Paeonia × lemoinei ‘High Noon’ established in this study is valuable for commercial use.
An efficient micropropagation protocol was developed for Paeonia × lemoinei ‘High Noon’ using axillary buds as explants. During initiation, 13 propagules were obtained after 50 d of culture with WPM + 0.5 mg/L BA + 0.2 mg/L GA3. During proliferation, three shoots were obtained after 35 d of culture with WPM[1668 mg/L Ca(NO3)2·4 H2O] + 0.5 mg/L BA + 0.2 mg/L GA3, and seven subcultures were carried out. For optimal rooting, the shoots were cultured with 1/2 MS (296 mg/L CaCl2) + 0.5 g/L activated charcoal for 20 d, then 1/2 MS (296 mg/L CaCl2) + 1.0 mg/L putrescine + 1.0 mg/L IBA for 30 d for root induction, and finally 1/2 MS (296 mg/L CaCl2) ＋ 4.0 g/L activated charcoal for 20 d for root development. The rooting percentage of the shoots was 77.2%. During acclimatization, the rooted plantlets were transferred to pots containing a mix of vermiculite/peat/perlite (1:1:1 V/V/V) substrate, and the survival rate was 92.1%. The micropropagation protocol for Paeonia × lemoinei ‘High Noon’ established in this study is valuable for commercial use.
2016, 34(1): 151-163.
DOI: 10.11913/PSJ.2095-0837.2016.10151
Abstract：
Compared with conventional identification keys, computer-based multi-access interactive keys have many advantages, e.g. easy to carry, update, identify, generate new data sets for additional scientific studies, promote dissemination of taxonomic knowledge and meet the needs of social development, as well as being straightforward, with a wide range of users. It is important for taxonomic researchers to develop Chinese interactive keys for identification of native plants. This study introduced characteristics, development and application of interactive keys for Chinese Orchidaceae. The family Orchidaceae is a flagship group for biodiversity conservation and other biological studies, including many species with medicinal and ornamental value. However, it is difficult to identify orchids because Orchidaceae are one of the largest plant families in China and worldwide. By referring to Flora Reipublicae Popularis Sinicae and Flora of China, we created an interactive key for Chinese orchids using the new self-developed program MagIden. This novel interactive key not only provides a powerful identification tool of Chinese orchids for researchers and the public, but also generates new data sets in MVSP and Bayesian format for further scientific studies. Interactive keys are a powerful tool for increasing the efficiency of taxonomic studies and identification because of their advantages in the collection, updating, and analysis of data.
Compared with conventional identification keys, computer-based multi-access interactive keys have many advantages, e.g. easy to carry, update, identify, generate new data sets for additional scientific studies, promote dissemination of taxonomic knowledge and meet the needs of social development, as well as being straightforward, with a wide range of users. It is important for taxonomic researchers to develop Chinese interactive keys for identification of native plants. This study introduced characteristics, development and application of interactive keys for Chinese Orchidaceae. The family Orchidaceae is a flagship group for biodiversity conservation and other biological studies, including many species with medicinal and ornamental value. However, it is difficult to identify orchids because Orchidaceae are one of the largest plant families in China and worldwide. By referring to Flora Reipublicae Popularis Sinicae and Flora of China, we created an interactive key for Chinese orchids using the new self-developed program MagIden. This novel interactive key not only provides a powerful identification tool of Chinese orchids for researchers and the public, but also generates new data sets in MVSP and Bayesian format for further scientific studies. Interactive keys are a powerful tool for increasing the efficiency of taxonomic studies and identification because of their advantages in the collection, updating, and analysis of data.
